Global warming has increased the interest worldwide to produce energy from climate-friendly renewable energy sources. Penetration of large-scale renewable energy sources as well as photovoltaic (PV) utilisation on the utility grid has created potential challenges including: voltage fluctuation, harmonic distortion, reactive power management as well as power quality (PQ) of the network. Ensuring appropriate harmonics in the line currents of PV integrated power system is one of the biggest challenges. This paper investigates the impacts of PV integration into the grid by experimental analysis, in particular, harmonics in the network. Several experiments were done with varying PV penetration and load using Renewable Energy Integration Facility (REIF) at CSIRO, Newcastle, Australia. Finally, adverse harmonic effects on the network has been analysed using Fast Fourier Transform (FFT). Experimental results show that harmonics across the network increases with the increase of PV penetration in the power systems network.